Plunger lift assembly

ABSTRACT

A plunger lift assembly is provided comprising a flow diverter that effects separation of gaseous material from reservoir fluid. The gaseous material may be collected to provide a source of pressurized gaseous material to displace the plunger for producing liquid reservoir fluid.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of and priority to U.S. ProvisionalPatent Application No. 62/518,845 filed Jun. 13, 2017, the contents ofwhich are incorporated herein by reference.

FIELD

The present disclosure relates to artificial lift systems, and relatedapparatuses, for use in producing hydrocarbon-bearing reservoirs, andassociated methods of manipulating such apparatuses and systems, and, inparticular, to plunger lift systems and methods of using such systems.

BACKGROUND

Gas interference is a problem encountered while producing wells,especially wells with horizontal sections. In producing reservoir fluidscontaining a significant fraction of gaseous material, the presence ofsuch gaseous material hinders production by contributing to sluggishflow. When plunger lift is required for assisting with production ofreservoirs using horizontal wells, slugging of liquid, being suppliedfor lifting the plunger, can also impede production.

SUMMARY

In one aspect, there is provided a reservoir fluid production assemblycomprising:

a reservoir fluid inlet for receiving reservoir fluid flow from adownhole wellbore space of the wellbore;

a downhole fluid conductor for conducting the received reservoir fluidflow;

a flow diverter fluidly coupled to the downhole fluid conductor suchthat the flow diverter receives reservoir fluid flow being conducted bythe downhole fluid conductor, and including:

-   -   a reservoir fluid discharge communicator for discharging the        received reservoir fluid into an uphole wellbore space of the        wellbore with effect that depletion of gaseous material, from        the received reservoir fluid, is effected by separation of the        gaseous material from the reservoir fluid within the wellbore        fluid conductor, in response to at least buoyancy forces, such        that a gaseous material-depleted reservoir fluid is obtained        while displacement of the reservoir fluid from the subterranean        formation is being effected such that the reservoir fluid is        being received by the conductor inlet and conducted to the        reservoir fluid discharge communicator via the reservoir fluid        receiver;    -   a gas-depleted reservoir fluid receiver for receiving the        obtained gas-depleted reservoir fluid and conducting the        gas-depleted reservoir fluid to a gas-depleted reservoir fluid        discharge communicator;        a sealed interface within the wellbore, between: (a) the uphole        wellbore space of the wellbore, and (b) the downhole wellbore        space of the wellbore, for preventing, or substantially        preventing, bypassing of the gas-depleted reservoir fluid        receiver by the gas-depleted reservoir fluid;        an uphole fluid conductor for conducting liquid reservoir fluid        to the produced liquid reservoir fluid outlet, and including a        liquid accumulator that is fluidly coupled to the gas-depleted        reservoir fluid discharge communicator for accumulating of        liquid reservoir fluid of the gas-depleted reservoir fluid that        is discharged from the gas-depleted reservoir fluid discharge        communicator;        a produced liquid reservoir fluid outlet; and        a plunger disposed within the uphole fluid conductor, uphole        relative to the gas-depleted reservoir fluid discharge        communicator of the flow diverter, and displaceable within the        uphole fluid conductor between a downhole position and an uphole        position;        wherein:

the plunger and the produced gas-depleted reservoir fluid outlet areco-operatively configured such that, while uphole-disposed liquidreservoir fluid is disposed uphole of the plunger, displacement of theplunger, from the downhole position to the uphole position, bypressurized gaseous material is with effect that the uphole-disposedliquid reservoir fluid is displaced uphole by the plunger and dischargedthrough the produced liquid reservoir fluid outlet; and

the plunger is configured for being conducted through liquid reservoirfluid that has accumulated within the liquid accumulator, while beingdisplaced from the uphole position to the downhole position bygravitational force in the absence of gaseous material that issufficiently pressurized to counterbalance the gravitational force, suchthat, after the plunger has passed through the accumulated liquidreservoir fluid, at least a fraction of the accumulated liquid reservoirfluid becomes disposed uphole relative to the plunger such that theuphole-disposed liquid reservoir fluid is obtained.

In another aspect a reservoir fluid production system is providedcomprising the assembly described above, wherein the assembly isdisposed within a wellbore.

BRIEF DESCRIPTION OF DRAWINGS

The preferred embodiments will now be described with reference to thefollowing accompanying drawings:

FIG. 1 is a schematic illustration of an embodiment of a systemincluding a reservoir fluid production assembly disposed within awellbore, with the plunger removed for clarity;

FIG. 2 is a schematic illustration of an embodiment of a flow diverterof the system illustrated in FIG. 1;

FIG. 3 is a schematic illustration of the system illustrated in FIG. 1,with the plunger disposed in the downhole position; and

FIG. 4 is a schematic illustration of the system illustrated in FIG. 1,with the plunger disposed in the uphole position.

DETAILED DESCRIPTION

As used herein, the terms “up”, “upward”, “upper”, or “uphole”, mean,relativistically, in closer proximity to the surface 106 and furtheraway from the bottom of the wellbore, when measured along thelongitudinal axis of the wellbore 102. The terms “down”, “downward”,“lower”, or “downhole” mean, relativistically, further away from thesurface 106 and in closer proximity to the bottom of the wellbore 102,when measured along the longitudinal axis of the wellbore 102.

Referring to FIG. 1, there are provided systems 8, with associatedapparatuses, for producing hydrocarbons from a reservoir, such as an oilreservoir, within a subterranean formation 100, when reservoir pressurewithin the oil reservoir is insufficient to conduct hydrocarbons to thesurface 106 through a wellbore 102.

The wellbore 102 can be straight, curved, or branched. The wellbore 102can have various wellbore portions. A wellbore portion is an axiallength of a wellbore 102. A wellbore portion can be characterized as“vertical” or “horizontal” even though the actual axial orientation canvary from true vertical or true horizontal, and even though the axialpath can tend to “corkscrew” or otherwise vary. The term “horizontal”,when used to describe a wellbore portion, refers to a horizontal orhighly deviated wellbore portion as understood in the art, such as, forexample, a wellbore portion having a longitudinal axis that is between70 and 110 degrees from vertical.

“Reservoir fluid” is fluid that is contained within an oil reservoir.Reservoir fluid may be liquid material, gaseous material, or a mixtureof liquid material and gaseous material. In some embodiments, forexample, the reservoir fluid includes water and hydrocarbons, such asoil, natural gas condensates, or any combination thereof.

Fluids may be injected into the oil reservoir through the wellbore toeffect stimulation of the reservoir fluid. For example, such fluidinjection is effected during hydraulic fracturing, water flooding, waterdisposal, gas floods, gas disposal (including carbon dioxidesequestration), steam-assisted gravity drainage (“SAGD”) or cyclic steamstimulation (“CSS”). In some embodiments, for example, the same wellboreis utilized for both stimulation and production operations, such as forhydraulically fractured formations or for formations subjected to CSS.In some embodiments, for example, different wellbores are used, such asfor formations subjected to SAGD, or formations subjected towaterflooding.

A wellbore string 113 is employed within the wellbore 102 forstabilizing the subterranean formation 100. In some embodiments, forexample, the wellbore string 113 also contributes to effecting fluidicisolation of one zone within the subterranean formation from anotherzone within the subterranean formation.

The fluid productive portion of the wellbore 102 may be completed eitheras a cased-hole completion or an open-hole completion.

A cased-hole completion involves running wellbore casing down into thewellbore through the production zone. In this respect, in the cased-holecompletion, the wellbore string 113 includes wellbore casing.

The annular region between the deployed wellbore casing and the oilreservoir may be filled with cement for effecting zonal isolation (seebelow). The cement is disposed between the wellbore casing and the oilreservoir for the purpose of effecting isolation, or substantialisolation, of one or more zones of the oil reservoir from fluidsdisposed in another zone of the oil reservoir. Such fluids includereservoir fluid being produced from another zone of the oil reservoir(in some embodiments, for example, such reservoir fluid being flowedthrough a production tubing string disposed within and extending throughthe wellbore casing to the surface), or injected fluids such as water,gas (including carbon dioxide), or stimulations fluids such asfracturing fluid or acid. In this respect, in some embodiments, forexample, the cement is provided for effecting sealing, or substantialsealing, of flow communication between one or more zones of the oilreservoir and one or more others zones of the oil reservoir (forexample, such as a zone that is being produced). By effecting thesealing, or substantial sealing, of such flow communication, isolation,or substantial isolation, of one or more zones of the oil reservoir,from another subterranean zone (such as a producing formation), isachieved. Such isolation or substantial isolation is desirable, forexample, for mitigating contamination of a water table within the oilreservoir by the reservoir fluid (e.g. oil, gas, salt water, orcombinations thereof) being produced, or the above-described injectedfluids.

In some embodiments, for example, the cement is disposed as a sheathwithin an annular region between the wellbore casing and the oilreservoir. In some embodiments, for example, the cement is bonded toboth of the production casing and the oil reservoir.

In some embodiments, for example, the cement also provides one or moreof the following functions: (a) strengthens and reinforces thestructural integrity of the wellbore, (b) prevents, or substantiallyprevents, produced reservoir fluid of one zone from being diluted bywater from other zones. (c) mitigates corrosion of the wellbore casing,(d) at least contributes to the support of the wellbore casing, and e)allows for segmentation for stimulation and fluid inflow controlpurposes.

The cement is introduced to an annular region between the wellborecasing and the oil reservoir after the subject wellbore casing has beenrun into the wellbore. This operation is known as “cementing”.

In some embodiments, for example, the wellbore casing includes one ormore casing strings, each of which is positioned within the well bore,having one end extending from the well head. In some embodiments, forexample, each casing string is defined by jointed segments of pipe. Thejointed segments of pipe typically have threaded connections.

Typically, a wellbore contains multiple intervals of concentric casingstrings, successively deployed within the previously run casing. Withthe exception of a liner string, casing strings typically run back up tothe surface 106.

For wells that are used for producing reservoir fluid, few of theseactually produce through wellbore casing. This is because producingfluids can corrode steel or form undesirable deposits (for example,scales, asphaltenes or paraffin waxes) and the larger diameter can makeflow unstable. In this respect, a production string is usually installedinside the last casing string. The production string is provided toconduct reservoir fluid, received within the wellbore, to the wellhead116. In some embodiments, for example. the annular region between thelast casing string and the production tubing string may be sealed at thebottom by a packer.

To facilitate flow communication between the reservoir and the wellbore,the wellbore casing may be perforated, or otherwise include per-existingports (which may be selectively openable, such as, for example, byshifting a sleeve), to provide a fluid passage for enabling flow ofreservoir fluid from the reservoir to the wellbore.

In some embodiments, for example, the wellbore casing is set short oftotal depth. Hanging off from the bottom of the wellbore casing, with aliner hanger or packer, is a liner string. The liner string can be madefrom the same material as the casing string, but, unlike the casingstring, the liner string does not extend back to the wellhead 116.Cement may be provided within the annular region between the linerstring and the oil reservoir for effecting zonal isolation (see below),but is not in all cases. In some embodiments, for example, this liner isperforated to effect flow communication between the reservoir and thewellbore. In this respect, in some embodiments, for example, the linerstring can also be a screen or is slotted. In some embodiments, forexample, the production tubing string may be engaged or stung into theliner string, thereby providing a fluid passage for conducting theproduced reservoir fluid to the wellhead 116. In some embodiments, forexample, no cemented liner is installed, and this is called an open holecompletion or uncemented casing completion.

An open-hole completion is effected by drilling down to the top of theproducing formation, and then casing the wellbore (with a wellborestring 113). The wellbore is then drilled through the producingformation, and the bottom of the wellbore is left open (i.e. uncased),to effect flow communication between the reservoir and the wellbore.Open-hole completion techniques include bare foot completions,pre-drilled and pre-slotted liners, and open-hole sand controltechniques such as stand-alone screens, open hole gravel packs and openhole expandable screens. Packers and casing can segment the open holeinto separate intervals and ported subs can be used to effect flowcommunication between the reservoir and the wellbore.

Referring to FIG. 1, an assembly 10 is provided for effecting productionof reservoir fluid from the reservoir 104. The assembly 10 includes aproduction string 202 that is disposed within the wellbore 102. Theproduction string 202 includes a production string inlet 204, a downholefluid conductor 206, a flow diverter 600, an uphole fluid conductor 610,and a production string outlet 208. Referring to FIGS. 3 and 4, theproduction string 202 also includes a plunger 300 (such as, for example,a free piston) for assisting production of liquid reservoir fluidthrough the outlet 208 from the reservoir 104. It is understood that theplunger 300 could be in the form of a single-piece construction, or amulti-piece construction.

As discussed above, the wellbore 102 is disposed in flow communication(such as through perforations provided within the installed casing orliner, or by virtue of the open hole configuration of the completion),or is selectively disposable into flow communication (such as byperforating the installed casing, or by actuating a valve to effectopening of a port), with the reservoir 104. When disposed in flowcommunication with the reservoir 104, the wellbore 102 is disposed forreceiving reservoir fluid flow from the reservoir 104.

The production string inlet 204 is for receiving, via the wellbore, thereservoir fluid flow from the reservoir. In this respect, the reservoirfluid flow enters the wellbore 102, as described above, and is thenconducted to the production string inlet 204. The production string 202includes a downhole fluid conductor 206, disposed downhole relative tothe flow diverter 600 for conducting the reservoir fluid flow, that isbeing received by the production string inlet, such that the reservoirfluid flow, that is received by the inlet 204, is conducted to the flowdiverter 600 via the downhole fluid conductor 206.

It is preferable to remove at least a fraction of the gaseous materialfrom the reservoir fluid flow being conducted within the productionstring 202, prior to the plunger 300, in order to mitigate gasinterference. The flow diverter 600, is provided to, amongst otherthings, perform this function. In this respect, the flow diverter 600 isdisposed downhole relative to the plunger 300. Suitable exemplary flowdiverters are described in International Application No.PCT/CA2015/000178, published on Oct. 1, 2015.

In some embodiments, for example, the flow diverter 600 is configuredsuch that the depletion of gaseous material from the reservoir fluidmaterial, that is effected while the assembly 10 is disposed within thewellbore 102, is effected externally of the flow diverter 600 within thewellbore 102, such as, for example, within an uphole wellbore space 108.

The flow diverter 600 includes a reservoir fluid receiver 602 (such as,for example, in the form of one or more ports) for receiving thereservoir fluid (such as, for example, in the form of a reservoir fluidflow) that is being conducted (e.g. flowed), via the downhole fluidconductor 206 of the production string 202, from the production stringinlet 204. In some embodiments, for example, the downhole fluidconductor 206 extends from the inlet 204 to the receiver 602 In someembodiments, for example, the reservoir fluid receiver 602 includes oneor more ports.

The flow diverter 600 also includes a reservoir fluid dischargecommunicator 604 (such as, for example, in the form of one or moreports) that is fluidly coupled to the reservoir fluid receiver 602 via areservoir fluid-conductor 603. The reservoir fluid conductor 603 definesone or more reservoir fluid conductor passages 603A (including, forexample, a network of passages). In some of the embodiments describedbelow, for example, the one or more reservoir fluid-conducting passages603A include the fluid passage 620A, the fluid passage 615A, and thefluid passage 622A. The reservoir fluid discharge communicator 604 isconfigured for discharging reservoir fluid (such as, for example, in theform of a flow) that is received by the reservoir fluid receiver 602 andconducted to the reservoir fluid discharge communicator 604 via thereservoir fluid conductor 603. In some embodiments, for example, thereservoir fluid discharge communicator 604 is disposed at an oppositeend of the flow diverter 600 relative to the reservoir fluid receiver602.

The flow diverter 600 also includes a gas-depleted reservoir fluidreceiver 608 (such as, for example, in the form of one or more ports)for receiving a gas-depleted reservoir fluid (such as, for example, inthe form of a flow), after gaseous material has been separated from thereservoir fluid (for example, a reservoir fluid flow), that has beendischarged from the reservoir fluid discharge communicator 604, inresponse to at least buoyancy forces. In this respect, the gas-depletedreservoir fluid receiver 608 and the reservoir fluid dischargecommunicator 605 are co-operatively configured such that thegas-depleted reservoir fluid receiver 608 is disposed for receiving agas-depleted reservoir fluid flow, after gaseous material has beenseparated from the received reservoir fluid flow that has beendischarged from the reservoir fluid discharge communicator 604, inresponse to at least buoyancy forces. In some embodiments, for example,the reservoir fluid discharge communicator 604 is disposed at anopposite end of the flow diverter 600 relative to the gas-depletedreservoir fluid receiver 608.

The flow diverter 600 also includes a gas-depleted reservoir fluidconductor 610 that includes a gas-depleted reservoir fluid-conductingpassage 610A configured for conducting the gas-depleted reservoir fluid(for example, a gas-depleted reservoir fluid flow) received by thereceiver 608 to a gas-depleted reservoir fluid discharge communicator611 (such as, for example, in the form of one or more ports). In someembodiments, for example, the gas-depleted reservoir fluid dischargecommunicator 611 is disposed at an opposite end of the flow diverter 600relative to the gas-depleted reservoir fluid receiver 608. Thegas-depleted reservoir fluid discharge communicator 611 is fordischarging gas-depleted reservoir fluid into a liquid accumulator 210Bof the uphole fluid conductor 210.

The assembly 10 also includes a wellbore sealed interface effector 400configured for interacting with a wellbore feature for defining awellbore sealed interface 500 within the wellbore 102, between: (a) anuphole wellbore space 108 of the wellbore 102, and (b) a downholewellbore space 110 of the wellbore 102, while the assembly 10 isdisposed within the wellbore 102. The sealed interface 500 prevents, orsubstantially prevents reservoir fluid, that is being received by thereservoir fluid receiver 608, from being conducted from the upholewellbore space 108 to the downhole wellbore space 110, therebypreventing, or substantially preventing, bypassing of gas-depletedreservoir fluid receiver 608 by gas-depleted reservoir fluid that hasbeen separated from the reservoir fluid within the uphole wellbore space108.

In this respect, in some embodiments, for example, the flow diverter 600and the wellbore sealed interface effector 400 are co-operativelyconfigured such that:

the reservoir fluid is discharged from the reservoir fluid dischargecommunicator 604 and conducted into the uphole wellbore space 108, suchthat the received reservoir fluid flow becomes disposed within theuphole wellbore space 108, and, while the received reservoir fluid isdisposed within the uphole wellbore space 108, gaseous material isseparated from the received reservoir fluid in response to at leastbuoyancy forces such that the gas-depleted reservoir fluid is obtainedand is supplied to the gas-depleted reservoir fluid receiver 608, andthe received gas-depleted reservoir fluid is conducted from thegas-depleted reservoir fluid receiver 608 to the liquid accumulator 210Bvia at least the conductor 610 and the gas-depleted reservoir fluiddischarge communicator 611;

while: (a) the assembly 10 is disposed within the wellbore 102 andoriented such that the production string inlet 204 is disposed downholerelative to (such as, for example, vertically below) the productionstring outlet, and the wellbore sealed interface 500 is defined byinteraction between the wellbore sealed interface effector 400 and awellbore feature; (b) displacement of the reservoir fluid from thesubterranean formation is being effected by the such that the reservoirfluid is being received by the inlet 204 (such as, for example, as areservoir fluid flow) and conducted to the reservoir fluid dischargecommunicator 604 via the reservoir fluid receiver 602.

The disposition of the sealed interface 500 is such that fluid flow,across the sealed interface 500, is prevented, or substantiallyprevented. In some embodiments, for example, the disposition of thesealed interface 500 is such that fluid flow, across the sealedinterface 500, in a downhole direction, from the uphole wellbore space108 to the downhole wellbore space 110, is prevented, or substantiallyprevented. In some embodiments, for example, the disposition of thesealed interface 500 is such that fluid, that is being conducted in adownhole direction within the intermediate fluid passage 112, isdirected to the gas-depleted reservoir fluid receiver 608. In thisrespect, the gas-depleted reservoir fluid, produced after the separationof gaseous material from the received reservoir fluid within the upholewellbore space 108, is directed to the gas-depleted reservoir fluidreceiver 608, and conducted to the liquid accumulator 210B via at leastthe conductor 610 and the gas-depleted reservoir fluid dischargecommunicator 611. The gas-depleted reservoir fluid, including a liquidreservoir fluid, collects within the liquid accumulator 210B.

In such embodiments, for example, the disposition of the sealedinterface 500 is effected by the combination of at least: (i) a sealed,or substantially sealed, disposition of the wellbore string 113 relativeto a polished bore receptacle 114 (such as that effected by a packer240A disposed between the wellbore string 113 and the polished borereceptacle 114), and (ii) a sealed, or substantially sealed, dispositionof the downhole production string portion 206 relative to the polishedbore receptacle 114 such that reservoir fluid flow, that is receivedwithin the wellbore 102 (that is lined with the wellbore string 113), isprevented, or substantially prevented, from bypassing the reservoirfluid receiver 602, and, as a corollary, is directed to the reservoirfluid receiver 602 for receiving by the reservoir fluid receiver 602.

In some embodiments, for example, the sealed, or substantially sealed,disposition of the downhole fluid conductor 206 relative to the polishedbore receptacle 114 is effected by a latch seal assembly. A suitablelatch seal assembly is a Weatherford™ Thread-Latch Anchor SealAssembly™.

In some embodiments, for example, the sealed, or substantially sealed,disposition of the downhole fluid conductor 206 relative to the polishedbore receptacle 114 is effected by one or more o-rings or seal-typeChevron rings. In this respect, the sealing interface effector 400includes the o-rings, or includes the seal-type Chevron rings.

In some embodiments, for example, the sealed, or substantially sealed,disposition of the downhole fluid conductor 206 relative to the polishedbore receptacle 114 is disposed in an interference fit with the polishedbore receptacle. In some of these embodiments, for example, the downholefluid conductor 206 is landed or engaged or “stung” within the polishedbore receptacle 114.

The above-described disposition of the wellbore sealed interface 500provide for conditions which minimize solid debris accumulation in thejoint between the downhole fluid conductor 206 and the polished borereceptacle 114 or in the joint between the polished bore receptacle 114and the casing 113. By providing for conditions which minimize soliddebris accumulation within the joint, interference to movement of theseparator relative to the liner, or the casing, as the case may be,which could be effected by accumulated solid debris, is mitigated.

In some embodiments, for example, the space, between: (a) thegas-depleted reservoir fluid receiver 608 of the flow diverter 600, and(b) the sealed interface 500, defines a sump 700 for collection of solidparticulate that is entrained within fluid being discharged from thereservoir fluid outlet ports 606 of the flow diverter 600, and the sump700 has a volume of at least 0.1 m³. In some embodiments, for example,the volume is at least 0.5 m³. In some embodiments, for example, thevolume is at least 1.0 m³. In some embodiments, for example, the volumeis at least 3.0 m³.

By providing for the sump 700 having the above-described volumetricspace characteristic, and/or the above-described minimum separationdistance characteristic, a suitable space is provided for collectingrelative large volumes of solid debris, such that interference by theaccumulated solid debris with the production of oil through the systemis mitigated. This increases the run-time of the system before anymaintenance is required. As well, because the solid debris is depositedover a larger area, the propensity for the collected solid debris tointerfere with movement of the flow diverter 600 within the wellbore102, such as during maintenance (for example, a workover) is reduced.

Referring to FIG. 1, in some embodiments, for example, the sealedinterface 500 is disposed within a section of the wellbore 14 whose axis14(a) is disposed at an angle “a” of at least 60 degrees relative to thevertical “V”. In some of these embodiments, for example, the sealedinterface 500 is disposed within a section of the wellbore whose axis isdisposed at an angle “α” of at least 85 degrees relative to the vertical“V”. In this respect, disposing the sealed interface 500 within awellbore section having such wellbore inclinations minimizes soliddebris accumulation at the sealed interface 500.

In some embodiments, for example, the wellbore 102 includes a wellborefluid conductor 102, such as, for example, the wellbore string 113 (suchas, for example, the casing 113), and the flow diverter 600 and thewellbore fluid conductor are co-operatively configured such that, whilethe assembly 10 is disposed within the wellbore 102 and oriented suchthat the production string inlet 204 is disposed downhole relative tothe production string outlet 208, an intermediate fluid passage 112 isdefined within the wellbore 102, between the flow diverter 600 and thewellbore fluid conductor 102 for effecting the flow communicationbetween the reservoir fluid discharge communicator 604 and thegas-depleted reservoir fluid receiver 608. In some embodiments, forexample, the intermediate fluid passage 112 is an annular space disposedbetween the flow diverter 600 and the wellbore fluid conductor 114.

Referring to FIGS. 1 and 2, in some embodiments, for example, while theassembly 10 is disposed within the wellbore 102, the reservoir fluiddischarge communicator 604 is oriented such that, while the assembly 10is disposed within the wellbore 102 and oriented such that theproduction string inlet 204 is disposed downhole relative to theproduction string outlet 208, a ray (see, for example ray 604A, whichcorresponds), that is disposed along the central longitudinal axis ofthe reservoir fluid discharge communicator, is disposed in an upholedirection at an acute angle of less than 30 degrees relative to thecentral longitudinal axis of the wellbore portion within which thediverter is disposed.

Again referring to FIGS. 1 and 2, in some embodiments, for example,while the assembly 10 is disposed within the wellbore 102, the reservoirfluid discharge communicator 604 is oriented such that, while theassembly 10 is disposed within the wellbore 102 and oriented such thatthe production string inlet 204 is disposed downhole relative to theproduction string outlet 208, a ray (see, for example ray 604A, whichcorresponds), that is disposed along the central longitudinal axis ofthe reservoir fluid discharge communicator 604, is disposed in an upholedirection at an acute angle of less than 30 degrees relative to thevertical (which includes disposition of the ray 6060 a along a verticalaxis).

In some embodiments, for example, the uphole wellbore space 108 extendsuphole from the discharge communicator 604, between the productionstring 202 and the wellbore fluid conductor 102, to a sealed interface800 within the wellbore to define a gaseous material accumulator 802 foraccumulating gaseous material. In some operational implementations, forexample, the accumulated gaseous material may be used for displacing theplunger 300 in an uphole direction, as described below.

In some embodiments, for example, the minimum cross-sectional flow areaof the uphole wellbore space is greater than the maximum cross-sectionalflow area of the intermediate fluid passage. In some embodiments, forexample, the ratio of the minimum cross-sectional flow area of theuphole wellbore space to the maximum cross-sectional flow area of theintermediate fluid passage is at least 1.2, such as, for example, atleast 1.3, such as, for example, at least 1.5, such as, for example, atleast 2.

In some embodiments, for example, the gas-depleted reservoir fluidreceiver 610 is disposed downhole relative to (such as, for example,vertically below) the reservoir fluid discharge communicator 604, whilethe assembly 10 is disposed within the wellbore 102 and oriented suchthat the production string inlet 204 is disposed downhole relative to(such as, for example, vertically below) the production string outlet208. In this respect, in some embodiments, for example, the flowdiverter 600 and the sealed interface effector 400 are co-operativelyconfigured such that, while: (a) the assembly 10 is disposed within thewellbore 102 and oriented such that the production string inlet 204 isdisposed downhole relative to (such as, for example, vertically below)the production string outlet 208, (b) the flow diverter 600 isintegrated into the assembly such that, while the assembly 10 isdisposed within the wellbore 102 and oriented such that the productionstring inlet 204 is disposed downhole relative to (such as, for example,vertically below) the production string outlet 208, the flow diverter600 is oriented such that the gas-depleted reservoir fluid receiver 608is disposed downhole relative to the reservoir fluid dischargecommunicator 604, and the wellbore sealed interface 500 is defined byinteraction between the wellbore sealed interface effector 400 and awellbore feature, and (c) displacement of the reservoir fluid from thesubterranean formation is being effected such that the reservoir fluidis being received by the inlet 204 (such as, for example, as a reservoirfluid flow) and conducted to the reservoir fluid discharge communicator604:

the reservoir fluid is discharged from the reservoir fluid dischargecommunicator 604 and into the uphole wellbore space 108, such that thereceived reservoir fluid becomes disposed within the uphole wellborespace 108, and, while the received reservoir fluid is disposed withinthe uphole wellbore space 108, gaseous material is separated from thereceived reservoir fluid in response to at least buoyancy forces suchthat the gas-depleted reservoir fluid is obtained, and the gas-depletedreservoir fluid is conducted downhole to the gas-depleted reservoirfluid receiver 608, and the gas-depleted reservoir fluid, received bythe gas-depleted reservoir fluid receiver 608, is conducted from thegas-depleted reservoir fluid receiver 608 to the gas-depleted reservoirfluid discharge communicator 611 via at least the conductor 610.

As above-described, the uphole fluid conductor 610 extends from thegas-depleted reservoir fluid discharge communicator 611 to the outlet608 for effecting flow communication between the discharge communicator611 and the outlet 608. In some embodiments, for example, downhole fluidconductor 206 defines a fluid passage 206A that has a maximumcross-sectional flow area that is less than the minimum cross-sectionalflow area of the fluid passage 210A defined by the uphole fluidconductor 210. In some embodiments, for example, the ratio of themaximum cross-sectional flow area of the fluid passage 206A of thedownhole fluid conductor 206 to the minimum cross-sectional flow area ofthe fluid passage 208A of the uphole fluid conductor 210 is less than0.85, such as, for example, less than 0.75, such as, for example, lessthan 0.65, such as, for example, less than 0.5, such as, for example,less than 0.25.

As alluded to above, the liquid accumulator 210B is fluidly coupled tothe gas-depleted reservoir fluid discharge communicator 611 foraccumulating liquid reservoir fluid of the gas-depleted reservoir fluidthat is being discharged from the gas-depleted reservoir fluid dischargecommunicator 611.

Referring to FIGS. 3 and 4, the plunger 300 is disposed within theuphole fluid conductor 210, uphole relative to the gas-depletedreservoir fluid discharge communicator 611 of the flow diverter 600. Theplunger 300 is displaceable within the uphole fluid conductor 210between a downhole position 212A (see FIG. 3) and an uphole position214A (see FIG. 4). In some embodiments, for example, a downhole stop 212is provided within the uphole fluid conductor 210 for limiting travel ofthe plunger 300 in the downhole direction and thereby establishing thedownhole position 212A. In some embodiments, for example, the downholestop 212 includes a bumper spring. In some embodiments, for example, anuphole stop 214 is provided within the uphole fluid conductor 210 forlimiting travel of the plunger 300 in the uphole direction and therebyestablishing the uphole position 214A. In some embodiments, for example,the uphole stop 214 includes a bumper spring. In some embodiments, forexample, a lubricator assembly is provided and includes the bumperspring which, amongst other things, functions as the uphole stop 214. Insome embodiments, for example, the lubricator assembly also includes aplunger catcher assembly.

The plunger 300 and the outlet 208 are co-operatively configured suchthat, while uphole-disposed liquid reservoir fluid is disposed uphole ofthe plunger 300, displacement of the plunger 300, from the downholeposition to the uphole position, by pressurized gaseous material is witheffect that the uphole-disposed liquid reservoir fluid is displaceduphole by the plunger 300 and discharged through the outlet 208. In thisrespect, while the plunger 300 is being displaced uphole by thepressurized gaseous material, the moving plunger 300 displaces theuphole-disposed liquid reservoir fluid in an uphole direction throughthe uphole fluid conductor 210 to the outlet 208.

The plunger 300 is also configured for being conducted through liquidreservoir fluid that has accumulated within the liquid accumulator 210B,while being displaced from the uphole position to the downhole positionby gravitational force in the absence of gaseous material that issufficiently pressurized to counterbalance the gravitational force. Thedownhole conduction of the plunger 300 is such that, after the plunger300 has passed through the accumulated liquid reservoir fluid, at leasta fraction of the accumulated liquid reservoir fluid becomes disposeduphole relative to the plunger 300 such that the uphole-disposed liquidreservoir fluid is obtained for being displaced by the plunger 300 thatis displaced by supplied pressurized gaseous material. In this respect,while the plunger 300 is being conducted downhole, by gravity, throughthe uphole fluid conductor 210, the accumulated liquid reservoir fluidis displaced uphole relative to the plunger 300 and becomes disposeduphole relative to the plunger 300 as uphole-disposed liquid reservoirfluid.

In this respect, in some embodiments, for example, the plunger 300 andthe uphole fluid conductor 210 are co-operatively configured such thatspacing between the plunger 300 and the uphole fluid conductor 210 aresufficiently small such that the uphole-disposed liquid reservoir fluiddoes not, or does not appreciably, fall back downhole relative to theplunger 300 (for example, because the gaseous material being flowed inan uphole direction prevents, or substantially prevents, such egress ofthe uphole-disposed liquid reservoir fluid.

Alternatively, in some embodiments, for example, the plunger 300includes a selectively openable fluid passage, extending therethrough,for permitting the accumulated liquid reservoir fluid to be conductedthrough the plunger 300, as the plunger 300 is being conducted downholethrough the accumulated liquid reservoir fluid, and also includes aone-way valve, such as, for example, a check valve, for preventing, orsubstantially preventing such liquid reservoir fluid, once disposeduphole relative to the plunger 300, from returning downhole relative tothe plunger 300.

As alluded to above, in some embodiments, for example, the pressurizedgaseous material, communicated to the plunger 300, and displacing theplunger from the downhole position to the uphole position, originatesfrom the gaseous material accumulator 802. Gaseous material beingreceived within the uphole wellbore portion 108 accumulates within thegaseous material accumulator 802 such that the accumulated gaseousmaterial becomes disposed at a pressure sufficient to effect the upholedisplacement of the plunger 300, and, in response, the plunger 300 isdisplaced uphole. To prevent, or substantially prevent, the accumulatedgaseous material from bypassing the plunger 300, a one-way valve 302,such as, for example, a check valve, is provided downhole of the flowdiverter within the downhole fluid conductor 206.

Alternatively, in some embodiments, for example, the pressurized gaseousmaterial is provided from an independent source 806. In this respect, insome embodiments, for example, a valve 804 is provided for controllingsupply of pressurized gaseous material into the uphole fluid conductor210 (such as, for example, via the flow diverter 600) for effecting theuphole displacement of the plunger 300. In some embodiments, forexample, a controller is provided for controlling operation of the valveto effect the necessary supplying of the pressurized gaseous material asrequired. In some embodiments, for example, the pressurized gaseousmaterial is supplied to the uphole fluid conductor 210 via the flowdiverter 600, and the one-way valve 302, such as, for example, a checkvalve, is provided within the downhole fluid conductor 206, downhole ofthe flow diverter 600, for preventing the pressurized gaseous materialfrom bypassing communication with the plunger 300.

In some embodiments, for example, an additional one-way valve 304 isdisposed between the liquid accumulator 210B and the gas-depletedreservoir fluid discharge communicator 611 for preventing fall-back ofliquid reservoir fluid that has collected within the liquid accumulator210B.

In some embodiments, for example, the assembly 10 is disposed within awellbore 102 including a vertical portion and a horizontal portion, andthe plunger 300 is disposed within the vertical portion. In thisrespect, by virtue of one or more features of the flow diverter 300, gasinterference is mitigated such that it becomes possible to disposed theplunger within the vertical portion. In some of these embodiments, forexample, the horizontal portion has a length, measured along alongitudinal axis of the horizontal portion, of at least 100 metres,such as, for example, at least 250 metres, such as, for example, atleast 500 metres.

In the above description, for purposes of explanation, numerous detailsare set forth in order to provide a thorough understanding of thepresent disclosure. However, it will be apparent to one skilled in theart that these specific details are not required in order to practicethe present disclosure. Although certain dimensions and materials aredescribed for implementing the disclosed example embodiments, othersuitable dimensions and/or materials may be used within the scope ofthis disclosure. All such modifications and variations, including allsuitable current and future changes in technology, are believed to bewithin the sphere and scope of the present disclosure. All referencesmentioned are hereby incorporated by reference in their entirety.

What is claimed is:
 1. A reservoir fluid production assembly comprising:a reservoir fluid inlet for receiving reservoir fluid flow from adownhole wellbore space of the wellbore; a downhole fluid conductor forconducting the received reservoir fluid flow; a flow diverter fluidlycoupled to the downhole fluid conductor such that the flow diverterreceives reservoir fluid flow being conducted by the downhole fluidconductor, and including: a reservoir fluid discharge communicator fordischarging the received reservoir fluid into an uphole wellbore spaceof the wellbore with effect that depletion of gaseous material, from thereceived reservoir fluid, is effected by separation of the gaseousmaterial from the reservoir fluid within the wellbore fluid conductor,in response to at least buoyancy forces, such that a gaseousmaterial-depleted reservoir fluid is obtained while displacement of thereservoir fluid from the subterranean formation is being effected suchthat the reservoir fluid is being received by the conductor inlet andconducted to the reservoir fluid discharge communicator via thereservoir fluid receiver; a gas-depleted reservoir fluid receiver forreceiving the obtained gas-depleted reservoir fluid and conducting thegas-depleted reservoir fluid to a gas-depleted reservoir fluid dischargecommunicator; a sealed interface within the wellbore, between: (a) theuphole wellbore space of the wellbore, and (b) the downhole wellborespace of the wellbore, for preventing, or substantially preventing,bypassing of the gas-depleted reservoir fluid receiver by thegas-depleted reservoir fluid; an uphole fluid conductor for conductingliquid reservoir fluid to the produced liquid reservoir fluid outlet,and including a liquid accumulator that is fluidly coupled to thegas-depleted reservoir fluid discharge communicator for accumulating ofliquid reservoir fluid of the gas-depleted reservoir fluid that isdischarged from the gas-depleted reservoir fluid discharge communicator;a produced liquid reservoir fluid outlet; and a plunger disposed withinthe uphole fluid conductor, uphole relative to the gas-depletedreservoir fluid discharge communicator of the flow diverter, anddisplaceable within the uphole fluid conductor between a downholeposition and an uphole position; wherein: the plunger and the producedgas-depleted reservoir fluid outlet are co-operatively configured suchthat, while uphole-disposed liquid reservoir fluid is disposed uphole ofthe plunger, displacement of the plunger, from the downhole position tothe uphole position, by pressurized gaseous material is with effect thatthe uphole-disposed liquid reservoir fluid is displaced uphole by theplunger and discharged through the produced liquid reservoir fluidoutlet; and the plunger is configured for being conducted through liquidreservoir fluid that has accumulated within the liquid accumulator,while being displaced from the uphole position to the downhole positionby gravitational force in the absence of gaseous material that issufficiently pressurized to counterbalance the gravitational force, suchthat, after the plunger has passed through the accumulated liquidreservoir fluid, at least a fraction of the accumulated liquid reservoirfluid becomes disposed uphole relative to the plunger such that theuphole-disposed liquid reservoir fluid is obtained.
 2. The assembly asclaimed in claim 1; wherein: the downhole fluid conductor extends fromthe reservoir fluid inlet to the reservoir fluid receiver and defines afluid passage; the uphole fluid conductor extends from the gas-depletedreservoir fluid discharge communicator to the produced liquid reservoirfluid outlet and defines a fluid passage; and the maximumcross-sectional flow area of the downhole fluid conductor is less thanthe minimum cross-sectional flow area of the uphole fluid conductor. 3.The assembly as claimed in claim 2; wherein the ratio of the maximumcross-sectional flow area of the downhole fluid conductor to the minimumcross-sectional flow area of the uphole fluid conductor is less than0.85.
 4. The assembly as claimed in any one of claims 1 to 3; whereinthe gas-depleted reservoir fluid receiver is disposed downhole relativeto the reservoir fluid discharge communicator.
 5. A reservoir fluidproduction system comprising: the assembly as claimed in any one ofclaims 1 to 4, wherein the assembly is disposed within a wellbore. 6.The system as claimed in claim 5; wherein: the wellbore includes avertical portion and a horizontal portion; and the plunger is disposedwithin the vertical portion.
 7. The system as claimed in claim 5 or 6;wherein the horizontal portion has a length, measured along alongitudinal axis of the horizontal portion, of at least 100 metres. 8.The system as claimed in any one of claims 5 to 7; wherein: anintermediate fluid passage is disposed between the flow diverter and thewellbore; and the minimum cross-sectional flow area of the upholewellbore space is greater than the maximum cross-sectional flow area ofthe intermediate fluid passage.
 9. The system as claimed in claim 8;wherein the ratio of the minimum cross-sectional flow area of the upholewellbore space to the maximum cross-sectional flow area of theintermediate fluid passage is at least 1.2.